Prior Primary Information Bar Codes
Bar codes and similar code recording arrangements are widely used today to mark objects in order to provide rapidly readable codes containing information relating to the object, such as, its identity or its price. For example, see The Bar Code Book: Reading, Printing, and Specification of Bar Code Symbols, by R. Palmer (Helmers Publishing, Inc., 1991); Lines of Communication: Bar Code and Data Collection Technology For the 90's, by C. Harmon (Helmers Publishing, Inc., 1994); Applying Industrial Bar Coding, by T. Sobczak (Society of Manufacturing Engineers, 1985); or Barcodes Galore: Maximize Productivity, by H. Burke (Tevaki Associates, 1992). Such codes usually consist of a horizontal series of printed vertical parallel bars of varying widths and spacings arranged to produce a particular reflectivity pattern when the bars are scanned sequentially in a straight line with a light beam such as, a laser beam, in a direction transverse to the orientation of the bars.
Most continuous manufacturing processes perform different operations at different stations in the assembly line. For example, in an engine block assembly line, a hole is drilled at one station, tapped at another and studded at yet another. Normally, a bar code may be used to store primary information relating to the product's identification, inventory, and pricing, etc. While it is known to provide such process information in a bar code, nonetheless, it is not known to provide such product-specific, process-specific tasks as a type of secondary information stored in a single bar code along with the aforesaid general primary information. Accordingly, there is a need for and it is an object of the present invention to provide a method for using the bar code having primary general product information and secondary process-specific information in a single bar code and a method for using such bar codes to control a manufacturing process involving object dependent tasks that rely on the secondary, process-specific information embedded within the primary bars.